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Publication numberUS20030177282 A1
Publication typeApplication
Application numberUS 09/902,812
Publication dateSep 18, 2003
Filing dateJul 10, 2001
Priority dateJul 10, 2001
Also published asUS7546602
Publication number09902812, 902812, US 2003/0177282 A1, US 2003/177282 A1, US 20030177282 A1, US 20030177282A1, US 2003177282 A1, US 2003177282A1, US-A1-20030177282, US-A1-2003177282, US2003/0177282A1, US2003/177282A1, US20030177282 A1, US20030177282A1, US2003177282 A1, US2003177282A1
InventorsAndres Hejlsberg, Brian Pepin, Chad Royal, Christopher Anderson, Giovanni Della-Libera, Mark Boulter, Nicholas Kramer, Shawn Burke, Subhag Oak, Sreeram Nivarthi
Original AssigneeAndres Hejlsberg, Pepin Brian K., Royal Chad W., Anderson Christopher L., Della-Libera Giovanni M., Boulter Mark A., Kramer Nicholas M., Burke Shawn P., Oak Subhag P., Sreeram Nivarthi
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Application program interface for network software platform
US 20030177282 A1
Abstract
An application program interface (API) provides a set of functions for application developers who build Web applications on Microsoft Corporation's .NET™ platform.
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Claims(40)
1. A software architecture for a distributed computing system comprising:
an application configured to handle requests submitted by remote devices over a network; and
an application program interface to present functions used by the application to access network and computing resources of the distributed computing system, the application program interface comprising various types related to constructing user interfaces.
2. A software architecture as recited in claim 1, wherein the various types comprise classes, interfaces, delegates, structures and enumerations.
3. A software architecture as recited in claim 1, wherein the distributed computing system comprises client devices and server devices that handle requests from the client devices, the remote devices comprising at least one client device.
4. A software architecture as recited in claim 1, wherein the distributed computing system comprises client devices and server devices that handle requests from the client devices, the remote devices comprising at least one server device that is configured as a Web server.
5. An application program interface embodied on one or more computer readable media, comprising: multiple types related to constructing user interfaces, the types comprising classes, interfaces, delegates, structures and enumerations.
6. An application program interface as recited in claim 5, wherein the classes comprise a forms class that represents a window or a dialog box that makes up an application's user interface.
7. An application program interface as recited in claim 6, wherein the forms class has multiple members comprising one or more of: public static properties, public static methods, public instance constructors, public instance methods, public instance properties, public instance events, protected instance properties, and protected instance methods.
8. An application program interface as recited in claim 5, wherein the type comprising the interfaces comprises a button control interface that allows a control to act like a button on a form.
9. An application program interface as recited in claim 5, wherein the type comprising the interfaces comprises a container control interface that provides functionality for a control to act as a parent for other controls.
10. An application program interface as recited in claim 5, wherein the type comprising the interfaces comprises an editing notification interface.
11. An application program interface as recited in claim 5, wherein the type comprising the interfaces comprises a data object interface that provides a format independent mechanism for transferring data.
12. An application program interface as recited in claim 5, wherein the type comprising the interfaces comprises a feature support interface that specifies a standard interface for retrieving feature information from a current system.
13. An application program interface as recited in claim 5, wherein the type comprising the interfaces comprises a message filter interface.
14. An application program interface as recited in claim 5, wherein the type comprising the interfaces comprises a handle-exposing interface to expose handles.
15. An application program interface as recited in claim 5, wherein the type comprising the interfaces comprises one or more of the following interfaces:
a button control interface that allows a control to act like a button on a form;
a container control interface that provides functionality for a control to act as a parent for other controls;
an editing notification interface;
a data object interface that provides a format independent mechanism for transferring data;
a feature support interface that specifies a standard interface for retrieving feature information from a current system;
a message filter interface; and
a handle-exposing interface to expose handles.
16. A distributed computer software architecture, comprising:
one or more applications configured to be executed on one or more computing devices, the applications handling requests submitted from remote computing devices;
a networking platform to support the one or more applications; and
an application programming interface to interface the one or more applications with the networking platform, the application programming interface comprising various types related to constructing user interfaces.
17. A distributed computer software architecture as recited in claim 16, wherein the various types comprise classes, interfaces, delegates, structures and enumerations.
18. A distributed computer software architecture as recited in claim 17, wherein the classes comprises a forms class that represents a window or a dialog box that makes up an application's user interface.
19. A distributed computer software architecture as recited in claim 18, wherein the forms class has multiple members comprising one or more of: public static properties, public static methods, public instance constructors, public instance methods, public instance properties, public instance events, protected instance properties, and protected instance methods.
20. A distributed computer software architecture as recited in claim 17, wherein the type comprising the interfaces comprises a button control interface that allows a control to act like a button on a form.
21. A distributed computer software architecture as recited in claim 17, wherein the type comprising the interfaces comprises a container control interface that provides functionality for a control to act as a parent for other controls.
22. A distributed computer software architecture as recited in claim 17, wherein the type comprising the interfaces comprises an editing notification interface.
23. A distributed computer software architecture as recited in claim 17, wherein the type comprising the interfaces comprises a data object interface that provides a format independent mechanism for transferring data.
24. A distributed computer software architecture as recited in claim 17, wherein the type comprising the interfaces comprises a feature support interface that specifies a standard interface for retrieving feature information from a current system.
25. A distributed computer software architecture as recited in claim 17, wherein the type comprising the interfaces comprises a message filter interface.
26. A distributed computer software architecture as recited in claim 17, wherein the type comprising the interfaces comprises a handle-exposing interface to expose handles.
27. A distributed computer software architecture as recited in claim 17, wherein the type comprising the interfaces comprises one or more of the following interfaces:
a button control interface that allows a control to act like a button on a form;
a container control interface that provides functionality for a control to act as a parent for other controls;
an editing notification interface;
a data object interface that provides a format independent mechanism for transferring data;
a feature support interface that specifies a standard interface for retrieving feature information from a current system;
a message filter interface; and
a handle-exposing interface to expose handles.
28. A computer system including one or more microprocessors and one or more software programs, the one or more software programs utilizing an application program interface to request services from an operating system, the application program interface including separate commands to request services comprising services related to constructing user interfaces.
29. A method, comprising:
managing network and computing resources for a distributed computing system; and
exposing a set of functions that enable developers to access the network and computing resources of the distributed computing system, the set of functions comprising functions to facilitate construction of user interfaces
30. A method as recited in claim 29, further comprising receiving a request from a remote computing device, the request containing a call to the set of functions.
31. A method, comprising creating a namespace with functions that enable drawing and construction of user interfaces, the name space defining classes, interfaces, delegates, structures and enumerations.
32. A method as recited in claim 31, wherein the namespace defines a forms class that represents a window or a dialog box that makes up an application's user interface.
33. A method as recited in claim 32, wherein the forms class has multiple members comprising one or more of: public static properties, public static methods, public instance constructors, public instance methods, public instance properties, public instance events, protected instance properties, and protected instance methods.
34. A method as recited in claim 31, wherein the namespace defines an interface comprising a button control interface that allows a control to act like a button on a form.
35. A method as recited in claim 31, wherein the namespace defines an interface comprising a container control interface that provides functionality for a control to act as a parent for other controls.
36. A method as recited in claim 31, wherein the namespace defines an interface comprising an editing notification interface.
37. A method as recited in claim 31, wherein the namespace defines an interface comprising a data object interface that provides a format independent mechanism for transferring data.
38. A method as recited in claim 31, wherein the namespace defines an interface comprising a feature support interface that specifies a standard interface for retrieving feature information from a current system.
39. A method as recited in claim 31, wherein the namespace defines an interface comprising a message filter interface.
40. A method as recited in claim 31, wherein the namespace defines an interface comprising a handle-exposing interface to expose handles.
Description
TECHNICAL FIELD

[0001] This invention relates to network software, such as Web applications, and to computer software development of such network software. More particularly, this invention relates to an application program interface (API) that facilitates use of a network software platform by application programs and computer hardware.

BACKGROUND

[0002] Very early on, computer software came to be categorized as “operating system” software or “application” software. Broadly speaking, an application is software meant to perform a specific task for the computer user such as solving a mathematical equation or supporting word processing. The operating system is the software that manages and controls the computer hardware. The goal of the operating system is to make the computer resources available to the application programmer while at the same time, hiding the complexity necessary to actually control the hardware.

[0003] The operating system makes the resources available via functions that are collectively known as the Application Program Interface or API. The term API is also used in reference to a single one of these functions. The functions are often grouped in terms of what resource or service they provide to the application programmer. Application software requests resources by calling individual API functions. API functions also serve as the means by which messages and information provided by the operating system are relayed back to the application software.

[0004] In addition to changes in hardware, another factor driving the evolution of operating system software has been the desire to simplify and speed application software development. Application software development can be a daunting task, sometimes requiring years of developer time to create a sophisticated program with millions of lines of code. For a popular operating system such as Microsoft Windows®, application software developers write thousands of different applications each year that utilize the operating system. A coherent and usable operating system base is required to support so many diverse application developers.

[0005] Often, development of application software can be made simpler by making the operating system more complex. That is, if a function may be useful to several different application programs, it may be better to write it once for inclusion in the operating system, than requiring dozens of software developers to write it dozens of times for inclusion in dozens of different applications. In this manner, if the operating system supports a wide range of common functionality required by a number of applications, significant savings in applications software development costs and time can be achieved.

[0006] Regardless of where the line between operating system and application software is drawn, it is clear that for a useful operating system, the API between the operating system and the computer hardware and application software is as important as efficient internal operation of the operating system itself.

[0007] Over the past few years, the universal adoption of the Internet, and networking technology in general, has changed the landscape for computer software developers. Traditionally, software developers focused on single-site software applications for standalone desktop computers, or LAN-based computers that were connected to a limited number of other computers via a local area network (LAN). Such software applications were typically referred to as “shrink wrapped” products because the software was marketed and sold in a shrink-wrapped package. The applications utilized well-defined APIs to access the underlying operating system of the computer.

[0008] As the Internet evolved and gained widespread acceptance, the industry began to recognize the power of hosting applications at various sites on the World Wide Web (or simply the “Web”). In the networked world, clients from anywhere could submit requests to server-based applications hosted at diverse locations and receive responses back in fractions of a second. These Web applications, however, were typically developed using the same operating system platform that was originally developed for standalone computing machines or locally networked computers. Unfortunately, in some instances, these applications do not adequately transfer to the distributed computing regime. The underlying platform was simply not constructed with the idea of supporting limitless numbers of interconnected computers.

[0009] To accommodate the shift to the distributed computing environment being ushered in by the Internet, Microsoft Corporation is developing a network software platform known as the “.NET” platform (read as “Dot Net”). The platform allows developers to create Web services that will execute over the Internet. Such a dynamic shift requires a new ground-up design of an entirely new API.

[0010] In response to this challenge, the inventors developed a unique set of API functions for Microsoft's .NET™ platform.

SUMMARY

[0011] An application program interface (API) provides a set of functions for application developers who build Web applications on a network platform, such as Microsoft Corporation's .NET™ platform.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The same numbers are used throughout the drawings to reference like features.

[0013]FIG. 1 illustrates a network architecture in which clients access Web services over the Internet using conventional protocols.

[0014]FIG. 2 is a block diagram of a software architecture for Microsoft's .NET™ platform, which includes an application program interface (API).

[0015]FIG. 3 is a block diagram of unique namespaces supported by the API, as well as function classes of the various API functions.

[0016]FIG. 4 is a block diagram of an exemplary computer that may execute all or part of the software architecture.

BRIEF DESCRIPTION OF ACCOMPANYING COMPACT DISC

[0017] Accompanying this specification is a compact disc that stores a compiled HTML help file identifying the API (application program interface) for Microsoft's .NET™ network platform. The file is named “cpref.chm” and was created on Jun. 8, 2001. It is 30.81 Mbytes in size. The file can be executed on a Windows®-based computing device (e.g., IBM-PC, or equivalent) that executes a Windows®-brand operating system (e.g., Windows® NT, Windows® 98, Windows® 2000, etc.). The compiled HTML help file stored on the compact disk is hereby incorporated by reference.

[0018] Additionally, the APIs contained in the compiled HTML help file are also provided in approximately 100 separate text files named “NamespaceName.txt”. The text files comply with the ASCII format.

[0019] The compact disc itself is a CD-ROM, and conforms to the ISO 9660 standard.

DETAILED DESCRIPTION

[0020] This disclosure addresses an application program interface (API) for a network platform upon which developers can build Web applications and services. More particularly, an exemplary API is described for the .NET™ platform created by Microsoft Corporation. The .NET™ platform is a software platform for Web services and Web applications implemented in the distributed computing environment. It represents the next generation of Internet computing, using open communication standards to communicate among loosely coupled Web services that are collaborating to perform a particular task.

[0021] In the described implementation, the .NET™ platform utilizes XML (extensible markup language), an open standard for describing data. XML is managed by the World Wide Web Consortium (W3C). XML is used for defining data elements on a Web page and business-to-business documents. XML uses a similar tag structure as HTML; however, whereas HTML defines how elements are displayed, XML defines what those elements contain. HTML uses predefined tags, but XML allows tags to be defined by the developer of the page. Thus, virtually any data items can be identified, allowing Web pages to function like database records. Through the use of XML and other open protocols, such as Simple Object Access Protocol (SOAP), the .NET™ platform allows integration of a wide range of services that can be tailored to the needs of the user. Although the embodiments described herein are described in conjunction with XML and other open standards, such are not required for the operation of the claimed invention. Other equally viable technologies will suffice to implement the inventions described herein.

[0022] As used herein, the phrase application program interface or API includes traditional interfaces that employ method or function calls, as well as remote calls (e.g., a proxy, stub relationship) and SOAP/XML invocations.

[0023] Exemplary Network Environment

[0024]FIG. 1 shows a network environment 100 in which a network platform, such as the .NET™ platform, may be implemented. The network environment 100 includes representative Web services 102(1), . . . , 102(N), which provide services that can be accessed over a network 104 (e.g., Internet). The Web services, referenced generally as number 102, are programmable application components that are reusable and interact programmatically over the network 104, typically through industry standard Web protocols, such as XML, SOAP, WAP (wireless application protocol), HTTP (hypertext transport protocol), and SMTP (simple mail transfer protocol) although other means of interacting with the Web services over the network may also be used, such as Remote Procedure Call (RPC) or object broker type technology. A Web service can be self-describing and is often defined in terms of formats and ordering of messages.

[0025] Web services 102 are accessible directly by other services (as represented by communication link 106) or a software application, such as Web application 110 (as represented by communication links 112 and 114). Each Web service 102 is illustrated as including one or more servers that execute software to handle requests for particular services. Such services often maintain databases that store information to be served back to requesters. Web services may be configured to perform any one of a variety of different services. Examples of Web services include login verification, notification, database storage, stock quoting, location directories, mapping, music, electronic wallet, calendar/scheduler, telephone listings, news and information, games, ticketing, and so on. The Web services can be combined with each other and with other applications to build intelligent interactive experiences.

[0026] The network environment 100 also includes representative client devices 120(1), 120(2), 120(3), 120(4), . . . , 120(M) that utilize the Web services 102 (as represented by communication link 122) and/or the Web application 110 (as represented by communication links 124, 126, and 128). The clients may communicate with one another using standard protocols as well, as represented by an exemplary XML link 130 between clients 120(3) and 120(4).

[0027] The client devices, referenced generally as number 120, can be implemented many different ways. Examples of possible client implementations include, without limitation, portable computers, stationary computers, tablet PCs, televisions/set-top boxes, wireless communication devices, personal digital assistants, gaming consoles, printers, photocopiers, and other smart devices.

[0028] The Web application 110 is an application designed to run on the network platform and may utilize the Web services 102 when handling and servicing requests from clients 120. The Web application 110 is composed of one or more software applications 130 that run atop a programming framework 132, which are executing on one or more servers 134 or other computer systems. Note that a portion of Web application 110 may actually reside on one or more of clients 120. Alternatively, Web application 110 may coordinate with other software on clients 120 to actually accomplish its tasks.

[0029] The programming framework 132 is the structure that supports the applications and services developed by application developers. It permits multi-language development and seamless integration by supporting multiple languages. It supports open protocols, such as SOAP, and encapsulates the underlying operating system and object model services. The framework provides a robust and secure execution environment for the multiple programming languages and offers secure, integrated class libraries.

[0030] The framework 132 is a multi-tiered architecture that includes an application program interface (API) layer 142, a common language runtime (CLR) layer 144, and an operating system/services layer 146. This layered architecture allows updates and modifications to various layers without impacting other portions of the framework. A common language specification (CLS) 140 allows designers of various languages to write code that is able to access underlying library functionality. The specification 140 functions as a contract between language designers and library designers that can be used to promote language interoperability. By adhering to the CLS, libraries written in one language can be directly accessible to code modules written in other languages to achieve seamless integration between code modules written in one language and code modules written in another language. One exemplary detailed implementation of a CLS is described in an ECMA standard created by participants in ECMA TC39/TG3. The reader is directed to the ECMA web site at www.ecma.ch.

[0031] The API layer 142 presents groups of functions that the applications 130 can call to access the resources and services provided by layer 146. By exposing the API functions for a network platform, application developers can create Web applications for distributed computing systems that make full use of the network resources and other Web services, without needing to understand the complex interworkings of how those network resources actually operate or are made available. Moreover, the Web applications can be written in any number of programming languages, and translated into an intermediate language supported by the common language runtime 144 and included as part of the common language specification 140. In this way, the API layer 142 can provide methods for a wide and diverse variety of applications.

[0032] Additionally, the framework 132 can be configured to support API calls placed by remote applications executing remotely from the servers 134 that host the framework. Representative applications 148(1) and 148(2) residing on clients 120(3) and 120(M), respectively, can use the API functions by making calls directly, or indirectly, to the API layer 142 over the network 104.

[0033] The framework may also be implemented at the clients. Client 120(3) represents the situation where a framework 150 is implemented at the client. This framework may be identical to server-based framework 132, or modified for client purposes. Alternatively, the client-based framework may be condensed in the event that the client is a limited or dedicated function device, such as a cellular phone, personal digital assistant, handheld computer, or other communication/computing device.

[0034] Developers' Programming Framework

[0035]FIG. 2 shows the programming framework 132 in more detail. The common language specification (CLS) layer 140 supports applications written in a variety of languages 130(1), 130(2), 130(3), 130(4), . . . , 130(K). Such application languages include Visual Basic, C++, C#, COBOL, Jscript, Perl, Eiffel, Python, and so on. The common language specification 140 specifies a subset of features or rules about features that, if followed, allow the various languages to communicate. For example, some languages do not support a given type (e.g., an “int*” type) that might otherwise be supported by the common language runtime 144. In this case, the common language specification 140 does not include the type. On the other hand, types that are supported by all or most languages (e.g., the “int[]” type) is included in common language specification 140 so library developers are free to use it and are assured that the languages can handle it. This ability to communicate results in seamless integration between code modules written in one language and code modules written in another language. Since different languages are particularly well suited to particular tasks, the seamless integration between languages allows a developer to select a particular language lo for a particular code module with the ability to use that code module with modules written in different languages. The common language runtime 144 allow seamless multi-language development, with cross language inheritance, and provide a robust and secure execution environment for the multiple programming languages. For more information on the common language specification 140 and the common language runtime 144, the reader is directed to co-pending applications entitled “Method and System for Compiling Multiple Languages”, filed Jun. 21, 2000 (Ser. No. 09/598,105) and “Unified Data Type System and Method” filed Jul. 10, 2000 (Ser. No. 09/613,289), which are incorporated by reference.

[0036] The framework 132 encapsulates the operating system 146(1) (e.g., Windows®-brand operating systems) and object model services 146(2) (e.g., Component Object Model (COM) or Distributed COM). The operating system 146(1) provides conventional functions, such as file management, notification, event handling, user interfaces (e.g., windowing, menus, dialogs, etc.), security, authentication, verification, processes and threads, memory management, and so on. The object model services 146(2) provide interfacing with other objects to perform various tasks. Calls made to the API layer 142 are handed to the common language runtime layer 144 for local execution by the operating system 146(1) and/or object model services 146(2).

[0037] The API 142 groups API functions into multiple namespaces. Namespaces essentially define a collection of classes, interfaces, delegates, enumerations, and structures, which are collectively called “types”, that provide a specific set of related functionality. A class represents managed heap allocated data that has reference assignment semantics. A delegate is an object oriented function pointer. An enumeration is a special kind of value type that represents named constants. A structure represents static allocated data that has value assignment semantics. An interface defines a contract that other types can implement.

[0038] By using namespaces, a designer can organize a set of types into a hierarchical namespace. The designer is able to create multiple groups from the set of types, with each group containing at least one type that exposes logically related functionality. In the exemplary implementation, the API 142 is organized into four root namespaces: a first namespace 200 for Web applications, a second namespace 202 for client applications, a third namespace 204 for data and XML, and a fourth namespace 206 for base class libraries (BCLs). Each group can then be assigned a name. For instance, types in the Web applications namespace 200 are assigned the name “Web”, and types in the data and XML namespace 204 can be assigned names “Data” and “XML” respectively. The named groups can be organized under a single “global root” namespace for system level APIs, such as an overall System namespace. By selecting and prefixing a top level identifier, the types in each group can be easily referenced by a hierarchical name that includes the selected top level identifier prefixed to the name of the group containing the type. For instance, types in the Web applications namespace 200 can be referenced using the hierarchical name “System.Web”. In this way, the individual namespaces 200, 202, 204, and 206 become major branches off of the System namespace and can carry a designation where the individual namespaces are prefixed with a designator, such as a “System.” prefix.

[0039] The Web applications namespace 200 pertains to Web based functionality, such as dynamically generated Web pages (e.g., Microsoft's Active Server Pages (ASP)). It supplies types that enable browser/server communication. The client applications namespace 202 pertains to drawing and client side UI functionality. It supplies types that enable drawing of two-dimensional (2D), imaging, and printing, as well as the ability to construct window forms, menus, boxes, and so on.

[0040] The data and XML namespace 204 relates to connectivity to data sources and XML functionality. It supplies classes, interfaces, delegates, and enumerations that enable security, specify data types, and serialize objects into XML format documents or streams. The base class libraries (BCL) namespace 206 pertains to basic system and runtime functionality. It contains the fundamental types and base classes that define commonly-used value and reference data types, events and event handlers, interfaces, attributes, and processing exceptions.

[0041] In addition to the framework 132, programming tools 210 are provided to assist the developer in building Web services and/or applications. One example of the programming tools 200 is Visual Studio™, a multi-language suite of programming tools offered by Microsoft Corporation.

[0042] Root API Namespaces

[0043]FIG. 3 shows the API 142 and its four root namespaces in more detail. In one embodiment, the namespaces are identified according to a hierarchical naming convention in which strings of names are concatenated with periods. For instance, the Web applications namespace 200 is identified by the root name “System.Web”. Within the “Sytem.Web” namespace is another namespace for Web services, identified as “System.Web.Services”, which further identifies another namespace for a description known as “System.Web.Services.Description”. With this naming convention in mind, the following provides a general overview of selected namespaces of the API 142, although other naming conventions could be used with equal effect.

[0044] The Web applications namespace 200 (“System.Web”) defines additional namespaces, including:

[0045] A services namespace 300 (“System.Web.Services”) containing classes that enable a developer to build and use Web services. The services namespace 300 defines additional namespaces, including a description namespace 302 (“System.Web.Services.Description”) containing classes that enable a developer to publicly describe a Web service via a service description language (such as WSDL, a specification available from the W3C), a discovery namespace 304 (“System.Web.Services.Discovery”) containing classes that allow Web service consumers to locate available Web Services on a Web server, and a protocols namespace 306 (“System.Web.Services.Protocols”) containing classes that define the protocols used to transmit data across a network during communication between Web service clients and the Web service itself.

[0046] A caching namespace 308 (“System.Web.Caching”) containing classes that enable developers to decrease Web application response time through temporarily caching frequently used resources on the server. This includes ASP.NET pages, web services, and user controls. (ASP.NET is the updated version of Microsoft's ASP technology.) Additionally, a cache dictionary is available for developers to store frequently used resources, such as hash tables and other data structures.

[0047] A configuration namespace 310 (“System.Web.Configuration”) containing classes that are used to read configuration data in for an application.

[0048] A UI namespace 312 (“System.Web.UI”) containing types that allow developers to create controls and pages that will appear in Web applications as user interfaces on a Web page. This namespace includes the control class, which provides all web based controls, whether those encapsulating HTML elements, higher level Web controls, or even custom User controls, with a common set of functionality. Also provided are classes which provide the web forms server controls data binding functionality, the ability to save the view state of a given control or page, as well as parsing functionality for both programmable and literal controls. Within the UI namespace 312 are two additional namespaces: an HTML controls namespace 314 (“System.Web.UI.HtmlControls”) containing classes that permit developers to interact with types that encapsulates html 3.2 elemtents create HTML controls, and a Web controls namespace 316 (“System.Web.UI.WeblControls”) containing classes that allow developers to create higher level Web controls.

[0049] A security namespace 318 (“System.Web.Security”) containing classes used to implement security in web server applications, such as basic authentication, challenge response authentication, and role based authentication.

[0050] A session state namespace 320 (“System.Web.SessionState”) containing classes used to access session state values (i.e., data that lives across requests for the lifetime of the session) as well as session-level settings and lifetime management methods.

[0051] The client applications namespace 202 is composed of two namespaces:

[0052] A windows forms namespace 322 (“System.Windows.Forms”) containing classes for creating Windows®-based client applications that take full advantage of the rich user interface features available in the Microsoft Windows® operating system, such as the ability to drag and drop screen elements. Such classes may include wrapped APIs available in the Microsoft Windows® operating system that are used in a windowing UI environment. Within this namespace are a design namespace 324 (“System.Windows.Forms.Design”) that contains classes to extend design-time support for Windows forms and a component model namespace 326 (“System.Windows.Forms.ComponentModel”) that contains the windows form implementation of the general component model defined in System.ComponentModel. This namespace contains designer tools, such as Visual Studio, which offer a rich experience for developers at design time.

[0053] A drawing namespace 328 (“System.Drawing”) containing classes for graphics functionality. The drawing namespace 328 includes a 2D drawing namespace 330 (“System.Drawing.Drawing2D”) that contains classes and enumerations to provide advanced 2-dimmensional and vector graphics functionality, an imaging namespace 332 (“System.Drawing.Imaging”) that contains classes for advanced imaging functionality, a printing namespace 334 (“System.Drawing.Printing”) that contains classes to permit developers to customize printing, and a text namespace 336 (“System.Drawing.Text”) that contains classes for advanced typography functionality.

[0054] The data and XML namespace 204 is composed of two namespaces:

[0055] A data namespace 340 (“System.Data”) containing classes that enable developers to build components that efficiently manage data from multiple data sources. It implements an architecture that, in a disconnected scenario (such as the Internet), provides tools to request, update, and reconcile data in multiple tier systems. The data namespace 340 includes a common namespace 342 that contains types shared by data providers. A data provider describes a collection of types used to access a data source, such as a database, in the managed space. The data namespace 340 also includes an OLE DB namespace 344 that contains types pertaining to data used in object-oriented databases (e.g., Microsoft's SQL Server), and a SQL client namespace 346 that contains types pertaining to data used by SQL clients. The data namespace also includes a SQL types namespace 348 (“System.Data.SqlTypes”) that contains classes for native data types within Microsoft's, SQL Server. The classes provide a safer, faster alternative to other data types. Using the objects within this namespace helps prevent type conversion errors caused in situations where loss of precision could occur. Because other data types are converted to and from SQL types behind the scenes, explicitly creating and using objects within this namespace results in faster code as well.

[0056] An XML namespace 350 (“System.XML”) containing classes that provide standards-based support for processing XML. The supported standards include XML (e.g., version 1.0), XML Namespaces (both stream level and DOM), XML Schemas, XPath expressions, XSL/T transformations, DOM Level 2 Core, and SOAP (e.g., version 1.1). The XML namespace 350 includes an XSLT namespace 352 (“System.XML.Xsl”) that contains classes and enumerations to support XSLT (Extensible Stylesheet Language Transformations), an Xpath namespace 354 (“System.XML.Xpath”) that contains an XPath parser and evaluation engine, and a serialization namespace 356 (“System.XML.Serialization”) that contains classes used to serialize objects into XML format documents or streams.

[0057] The base class library namespace 206 (“System”) includes the following namespaces:

[0058] A collections namespace 360 (“System.Collections”) containing interfaces and classes that define various collections of objects, such as lists, queues, arrays, hash tables and dictionaries.

[0059] A configuration namespace 362 (“System.Configuration”) containing classes and interfaces that allow developers to programmatically access configuration settings and handle errors in configuration files.

[0060] A diagnostics namespace 364 (“System.Diagnostics”) containing classes that are used to debug applications and to trace code execution. The namespace allows developers to start system processes, read and write to event logs, and monitor system performance using performance counters.

[0061] A globalization namespace 366 (“System.Globalization”) containing classes that define culture-related information, including the language, the country/region, the calendars in use, the format patterns for dates, currency and numbers, and the sort order for strings.

[0062] An I/O namespace 368 (“System.IO”) containing the infrastructure pieces to operate with the intput/output of data streams, files, and directories. This namespace includes a model for working with streams of bytes, higher level readers and writers which consume those bytes, various constructions or implementations of the streams (e.g., FileStream and MemoryStream) and, a set of utility classes for working with files and directories.

[0063] A net namespace 370 (“System.Net”) providing an extensive set of classes for building network-enabled application, referred to as the Net Class Libraries (NCL). One element to the design of the Net Class Libraries is an extensible, layered approach to exposing networking functionality. The NCL stack contains three basic layers. A base layer (System.Net.Socket) provides access to an interface to TCP/IP, the communications protocol of UNIX networks and the Internet. One example of such an interface is the “WinSock API” from Microsoft Corporation. The next layer is the Transport Protocol classes, which support such transport protocols as TCP and UDP. Developers may write their own protocol classes to provide support for protocols such as IGMP and ICMP. The third layer is the Web request, which provides an abstract factory pattern for the creation of other protocol classes. The NCL provides implementations for Hyper Text Transport Protocol (HTTP).

[0064] A reflection namespace (“System.Reflection”) 372 containing types that provide a managed view of loaded types, methods, and fields, with the ability to dynamically create and invoke types.

[0065] A resources namespace 374 (“System.Resources”) containing classes and interfaces that allow developers to create, store and manage various culture-specific resources used in an application.

[0066] A security namespace 376 (“System.Security”) supporting the underlying structure of the security system, including interfaces, attributes, exceptions, and base classes for permissions.

[0067] A service process namespace 378 (“System.ServiceProcess”) containing classes that allow developers to install and run services. Services are long-running executables that run without a user interface. They can be installed to run under a system account that enables them to be started at computer reboot. Services whose implementation is derived from processing in one class can define specific behavior for start, stop, pause, and continue commands, as well as behavior to take when the system shuts down.

[0068] A text namespace 380 (“System.Text”) containing classes representing various types of encodings (e.g., ASCII, Unicode, UTF-7, and UTF-8), abstract base classes for converting blocks of characters to and from blocks of bytes, and a helper class that manipulates and formats string objects without creating intermediate instances.

[0069] A threading namespace 382 (“System.Threading”) containing classes and interfaces that enable multi-threaded programming. The threading namespace includes a ThreadPool class that manages groups of threads, a Timer class that enables a delegate to be called after a specified amount of time, and a Mutex class for synchronizing mutually-exclusive threads. This namespace also provides classes for thread scheduling, wait notification, and deadlock resolution.

[0070] A runtime namespace 384 (“System.Runtime”) containing multiple namespaces concerning runtime features, including an interoperation services namespace 386 (“System.Runtime.InteropServices”) that contains a collection of classes useful for accessing COM objects. The types in the InteropServices namespace fall into the following areas of functionality: attributes, exceptions, managed definitions of COM types, wrappers, type converters, and the Marshal class. The runtime namespace 384 further includes a remoting namespace 388 (“System.Runtime.Remoting”) that contains classes and interfaces allowing developers to create and configure distributed applications. Another namespace within the runtime namespace 384 is a serialization namespace 390 (“System.Runtime.Serialization”) that contains classes used for serializing and deserializing objects. Serialization is the process of converting an object or a graph of objects into a linear sequence of bytes for either storage or transmission to another location.

[0071] The following description pertains to the “.forms” namespace and describes various types associated with the namespace as well as the functionalities provided by the various types.

[0072] 1. System.Windows.Forms.Design

[0073] The namespace contains classes that can be used to extend design-time support for Windows Forms.